edu.illinois.cs.cogcomp.edison.features

Class ContextFeatureExtractor

java.lang.Object

edu.illinois.cs.cogcomp.edison.features.FeatureCollection

edu.illinois.cs.cogcomp.edison.features.ContextFeatureExtractor

All Implemented Interfaces:

FeatureExtractor

public class ContextFeatureExtractor
extends FeatureCollection

A ContextFeatureExtractor generates features from the words in the context of the specified constituent. The constructor specifies the context size.

To use this class, after creating the object, add other feature extractors using the FeatureCollection.addFeatureExtractor(FeatureExtractor) method. Then, for each neighboring word, the feature extractor will generate features using all the extractors that have been added.

Note: This class only generates features from neighboring words. To go beyond words, new code needs to be written as required.

Author:

Vivek Srikumar

Field Summary

Fields inherited from class edu.illinois.cs.cogcomp.edison.features.FeatureCollection

generators

Constructor Summary

Constructors

Constructor and Description
ContextFeatureExtractor(int contextSize, boolean specifyIndex, boolean ignoreConstituent) Create a new ContextFeatureExtractor.
ContextFeatureExtractor(int contextSize, boolean specifyIndex, boolean ignoreConstituent, WordFeatureExtractor... fex)

Method Summary

Modifier and Type	Method and Description
Set<Feature>	getFeatures(Constituent c)
String	getName()

Methods inherited from class edu.illinois.cs.cogcomp.edison.features.FeatureCollection

addFeatureExtractor

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ContextFeatureExtractor

public ContextFeatureExtractor(int contextSize,
                               boolean specifyIndex,
                               boolean ignoreConstituent)

Create a new ContextFeatureExtractor.

Parameters:

contextSize - The number of tokens to the left and right of the constituent from which the features should be extracted.

specifyIndex - Should the feature mention the index (relative to the constituent)

ignoreConstituent - Should the tokens in the constituent itself be ignored while generating the features.

ContextFeatureExtractor

public ContextFeatureExtractor(int contextSize,
                               boolean specifyIndex,
                               boolean ignoreConstituent,
                               WordFeatureExtractor... fex)

Method Detail

getFeatures

public Set<Feature> getFeatures(Constituent c)
                         throws EdisonException

Specified by:

getFeatures in interface FeatureExtractor

Overrides:

getFeatures in class FeatureCollection

Throws:

EdisonException

getName

public String getName()

Specified by:

getName in interface FeatureExtractor

Overrides:

getName in class FeatureCollection